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PubMed1980

A micropuncture study of transepithelial water reabsorption in rat ductuli efferentes.

Micropuncture techniques were used to study transepithelial water reabsorption in single tubular sections of rat ductuli efferentes in vivo and in situ. Fluid reabsorption was found to be secondary to an electrolyte transport process. It was completely abolished by intraluminal application of 10(-4) M amiloride and by an elevated local temperature of 38 degrees C. The fluid reabsorption rate was modified by the intraluminal electrolyte concentration, whereas various local temperatures from 37 degrees C to room temperature had no effect. This finding led to the conclusion that the function of the ductuli efferentes may require temperatures lower than body temperature, which is in accordance with the well-known behavior of mammalian testes. It was further suggested that the described fluid reabsorption leads to concentrations of spermatozoa and of substrates which spermatozoa may need to develop and mature.

Absorption↗
PubMed1978

Ductuli efferentes in the epididymis of boar, goat, ram, bull, and stallion.

Dutculi efferentes were studied by microdissection and histologic methods in 2 boar, 6 goat, 5 ram, 25 bull, and 19 stallion epididymides. On the basis of the present findings and the data of others and relating them to the total number of specimens examined in each species, an estimate (narrow range) was made of the minimal-maximal numbers of efferent ductules as follows: dog 13 to 15; cat 14 to 17; boar 14 to 16; goat 18 to 19; ram 17 to 20; bull 13 to 16; and stallion 14 to 17. The histologic appearance of the efferent ductules of the bull, including measurements of their diameter, lumen, and epithelium, was briefly described. Attention was focused on the presence of blind-ending ductules, because it was thought that they might be a factor in the cause of spermiostasis. Blind-ending ductules were found in 1 of 2 porcine, 1 of 6 caprine, 2 of 5 ovine, 8 of 25 bovine, and 13 of 19 equine ductules per affected male were 4 in the boar, 1 in the goat, 2 to 3 in the ram, 1 to 5 in the bull, and 1 to 14 in the stallion. From our work, it appears that in the bull and stallion at least, blind-ending ductules were present in sufficient numbers to be considered a factor in spermiostasis and the infertility resulting from it.

Animals↗
PubMedDate not supplied

Testosterone and spermatogenesis: evidence that androgens regulate cellular secretory mechanisms in stage VI-VIII seminiferous tubules from adult rats.

The aim of this study was to investigate the effect of testosterone manipulation on the quantitative synthesis and secretion of a number of specific proteins produced by seminiferous tubules (ST) isolated at stages VI-VIII of the spermatogenic cycle from adult rats. The proteins selected were derived from different cellular sources. ST were isolated from control rats, from rats treated 4 days earlier with ethane dimethane sulfonate (EDS) to induce complete testosterone withdrawal by the destruction of the Leydig cells, and from EDS-treated rats injected with testosterone esters (TE) in order to maintain quantitatively normal spermatogenesis. Two-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis, combined with computerized image analysis, was used to analyze 35S-methionine-labeled intracellular and secreted proteins. Testosterone withdrawal did not affect to any significant degree the total synthesis of any of the proteins studied. Similarly, the secretion of the major known Sertoli cell proteins SGP-1 and SGP-2, together with a third putative Sertoli cell protein, all of which appeared to be secreted constitutively, was also not affected to any major degree by EDS treatment. In contrast, the secretion of another probable Sertoli cell protein, together with six proteins found to be secreted by germ cells and one protein that appeared to derive from more than one cellular source, was reduced dramatically by testosterone withdrawal, but was maintained by treatment with EDS+TE. All of the affected proteins appeared to be secreted in a regulated manner. Our results confirm that testosterone manipulation has little or no effect on either total protein synthesis by ST, or on the secretion of the major Sertoli cell secretory proteins, at stages VI-VIII of the spermatogenic cycle, but suggest strongly that testosterone regulation of ST protein secretion at these stages is mediated by an effect on the regulated secretory pathways. Our findings also demonstrate that the secretion, not only of Sertoli cell proteins, but also of those secreted by germ cells, is androgen-regulated.

Actins↗
PubMed1998

[The development of the horse testis].

The aim of the study was to answer the open questions concerning the development of the horse's testis. This study revealed that the seminiferous tubules originate from the sex cords of the coelomic epithelium and Leydig cells from the proximal part of mesonephric nephrons, whereas the rete and the ductuli efferentes derive from intermediate and distal parts of the mesonephric tubules. During the development the Leydig cells undergo an enormous proliferation due to the PMSG secretion in the mare. The proliferation of these cells prevent the deep penetration of the rete into the medulla and is therefore the reason for the reduced extension of the rete and mediastinum testis in the stallion, although 80% of these cells degenerate in the last third of pregnancy. The growth of the seminiferous tubules during sexual maturity reduces the rete to the extremitas capitata of the testis.

Animals↗
PubMed1993

Pathology of 46,XY pure gonadal dysgenesis: absence of testis differentiation associated with mutations in the testis-determining factor.

Individuals with 46, XY pure gonadal dysgenesis present with a completely female phenotype. These individuals develop bilateral streak gonads and have normal Müllerian structures. The apparent absence of testicular tissue in these individuals suggests a mutation in the initial steps of the male sex-determining pathway. A candidate gene for the primary signal in this pathway was recently cloned (SRY) which encodes a protein with a DNA-binding capacity. In a study of 14 XY females with pure gonadal dysgenesis harbouring SRY, we analysed the histology of the gonads and compared it to the presence or absence of mutations in the SRY open reading frame (SRY-orf). The histological analysis revealed two distinct groups of streak gonads. In the first group, the gonad was composed of exclusively ovarian-like stroma, with sclero-hyaline nodules in some areas. No tubules were observed. The gonads in the second group were composed of undifferentiated stroma harbouring either tubules or a rete structure. This suggests that in the latter group some differentiation (towards testis formation) has occurred, whereas in the first group ovarian differentiation has been interrupted. Individuals with mutations in the SRY-orf were found to have streak gonads of the first group, whereas most of the remaining XY females without detectable mutation in the SRY-orf had streak gonads belonging to the second group. On the basis of histology, it may be possible to distinguish between mutations in the sex-determining or sex-differentiation pathways. We suggest that SRY may play a role in rete testis formation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed2004

Excurrent duct system of the male turtle Chrysemys picta.

The epididymis and efferent duct system of the turtle Chrysemys picta were examined. Seminiferous tubules are drained by a series of ducts that form a rete exterior to the tunica albuginea. The rete is located lateral to the testis and consists of anastamosing tubules of varying diameters, lined by a simple epithelium consisting of squamous to cuboidal cells. The rete is highly vascularized. A series of tubules (efferent ductules) connect the rete to the epididymis proper. The efferent ductules are highly convoluted, running between the epididymal tubules and are of varying diameters. The simple columnar epithelium lining these tubules possesses tight junctions, with every third or fourth cell possessing long cilia that protrude into the lumen. The cytoplasm of these epithelial cells contains abundant mitochondria. In the central portion of the efferent ductule, epithelial cells possess granules that appear to be secreted into the lumen by an apocrine process. The epididymis proper is a single, long, highly convoluted tubule that receives efferent ductules along its entire length. It is lined by a pseudostratified epithelium containing several cell types. The most abundant cell (vesicular cell) lacks cilia, but has a darkly staining apical border due to numerous small vesicles immediately beneath the luminal membrane. The small vesicles appear to fuse with each other basally to form larger vesicles. These cells appear to have an absorptive function, and occasionally sperm are embedded in their cytoplasm. The second-most abundant cell is a basal cell found along the basement membrane. The number of these cells fluctuates throughout the year, being most abundant in late summer and early fall. A small narrow cell with an oval nucleus and darkly staining cytoplasm, extending from the basement membrane to the apical surface, is present in small numbers, particularly in the caudal regions of the epididymis. This cell is frequently found in association with another narrow cell having a rounded nucleus and abundant mitochondria in its cytoplasm.

Animals↗
PubMed1996

Immunohistolocalization of the carbonic anhydrase isoenzymes (CA-I, CA-II, and CA-III) in the reproductive tract of male horses.

OBJECTIVE: To elucidate locations of cytosolic carbonic anhydrase isoenzyme (CA-I, CA-II, and CA-III)-positive epithelial cells in equine male reproductive organs. DESIGN: Descriptive and immunohistochemical study. ANIMALS: 4 clinically normal male horses. PROCEDURE: The testis (seminiferous tubules, rete tubules), epididymis (initial, middle, and terminal segments), proximal and distal portions of the ductus deferens, ampulla ductus deferentis, seminal vesicle, prostate, and bulbourethral gland were excised from euthanatized horses after administration of an overdose of pentobarbital. The tissue specimens were quickly placed in fixative solution, dehydrated in ethanol, and embedded; then thin sections were cut. For immunohistochemical staining, antibodies against purified equine CA-I, CA-II, and CA-III were raised in rabbits. After examination of the specificity of each antiserum, the monospecific antisera against carbonic anhydrase isoenzymes were used to localize the isoenzymes. RESULTS: Specific staining for CA-III was found in the Sertoli and basal cells of the ductus deferens. Most of the testicular and epididymal tissue, as well as ductus deferens, were virtually negative for the enzymes when stained with the antibody to CA-I and CA-II. In the initial segment of the epididymis, a few principal cells had intense cytoplasmic staining with anti-CA-II. In the male accessory glands, CA-I, CA-II, and CA-III were detected in the epithelial cells of the seminal vesicle, prostate, and bulbourethral gland. CONCLUSIONS: In the equine male reproductive tract, the bicarbonate in semen originates mainly from accessory reproductive glands. All 3 isoenzymes may have central roles in the regulation of bicarbonate concentration in seminal plasm and, accordingly, regulate seminal plasma pH. Distribution of CA-III in Sertoli and basal cells of the ductus deferens suggests other specialized physiologic roles.

Animals↗
PubMed1990

Germinal cell ectopism in the strepsirhine prosimian Galago crassicaudatus crassicaudatus.

The presence of germinal cells outside of the embryonal and fetal gonads of the strepsirhine prosimian Galago crassicaudatus crassicaudatus is described. Forty-three embryos and fetuses from day 26 or 27 of gestational age to near term were studied: more than 90% possessed germinal cells in ectopic sites situated either far from (extragonadal ectopism) or close to the gonads (perigonadal ectopism). The first sites were the walls of the aorta and mesenteric artery, the stroma between the aorta and the cardinal vein, and the retroperitoneal neuroganglia. The second were the mesenchyme dorsal to the gonads and around the vestigia of the mesonephric glomeruli and tubules, and the rete ovarii and testis. The ectopic cells were generally present in conscpicuous numbers, in some animals being more numerous than in the gonads. Those situated far from the gonads underwent degeneration and decreased significantly in numbers during post-embryonal stages of development, while the others remained numerous and functionally active up to near term. While the differentiation of the extragonadal germinal cells after day 60 of gestational age could not be studied due to technical difficulties, the XX and XY cells in perigonadal sites appeared to follow patterns of differentiation identical to those of their entopic counterparts.

Animals↗
PubMed1989

The mediastinum of the bovine testis.

The bovine testis has a central mediastinum consisting of longitudinally oriented rete channels and spacious lymph vessels, embedded in the mediastinal stroma. The latter represents a contractile-elastic unit and is composed of myofibroblasts, collagen bundles and accumulations of elastin, connecting the myofibroblasts. The dimension of the mediastinum varies in cross sections at different levels between 3.5 and 31.8 mm2. In one cross section approximately 30 rete channels and approximately 30 openings of straight testicular tubules are encountered. Nearly 25% of the area is occupied by thin-walled, valveless lymph vessels. Arterial convolutes, interpolated between straight centripetal and straight centrifugal branches of the testicular artery flank the rete on all sides. It is concluded that the pulsation within these convolutes together with the contractile-elastic stroma promotes lymph and rete content in a caudo-cranial direction. Chordae retis as described by Roosen-Runge and Holstein (1978) for the human testis are a common feature in the bovine mediastinum testis. The rete channels are lined by a simple cuboidal or columnar epithelium. Short intraepithelial crypts are present and function as epithelial reserve for dilatation and expansion of the rate. The inventory of organelles is rather inconspicuous in the rete epithelium. The apical border bears short microvilli and gives a strong reaction for alkaline phosphatase. The basal cytoplasm contains many small to medium-sized electron-dense bodies and is site of a strong acid phosphatase reaction. The rete epithelium as a whole reacts strongly with leucine aminopeptidase, the marker enzyme of the testicular excurrent duct system. Many free mononuclear cells, mostly macrophages, are observed in the basal half of the rete epithelium.

Animals↗
PubMed1980

A comparative study of the development of the fetal testis and ovary in the monkey (Macaca fascicularis).

The gonadal development of the Macaca fascicularis fetus was studied between 37 and 118 days on serial semi-thin and thin sections. The testis and the ovary began to differentiate at the same age (37 days); the definitive architecture of the testis was acquired at 43 days, while a cortex and a medulla did not form in the ovary until 55 to 60 days. In spite of the time-lag and the divergent development, the testis and the ovary evidenced three comparable stages; the main event of these stages was the centrifugal role of the mesonephros. The first stage (37-43 days) included the centrifugal and antero-posterior differentiation of the sex cord anlages from the mesonephric mesenchyme in contact with the proximal loops of the anterior tubules (for a detailed study see Dang and Fouquet, 1979). From 43 days (second stage), a remainder of the mesonephric mesenchymal blastema of the gonad supplied the rete system. The mesonephric tubules fused secondarily with that system which was connected to the sex cords. Whereas in the testis, the rete blastema did not play a direct role in organizing testicular structures, but only in forming excretory pathways, in the ovary, it invaded the medulla (whose initial sex cords degenerated) and penetrated to the ovigerous cords of the cortex. The rete ovarii blastema was probably the major source of periovocyte cells. The third stage included the differentiation of a steroidogenic interstitial tissue (from 50 days in the testis; at about 60 days in the ovary) and is further involution; these processes were similar in both sexes. Observation of the fine structure showed the development of the male and female gonocytes to be the same; the prespermatogonia and the oogonia could be characterized by the formation of nuclear vacuoles. The Sertoli cells and the periovogonial cells showed the same features.

Animals↗
PubMedDate not supplied

Suppression of androgen action and the induction of gross abnormalities of the reproductive tract in male rats treated neonatally with diethylstilbestrol.

This study evaluated whether androgen action is altered in rats treated neonatally with diethylstilbestrol (DES) at a dose that induced reproductive tract abnormalities. Rats were treated on alternate days 2-12 with 10 microg DES and studied on Day 18. DES-induced abnormalities included a 70% reduction in testis weight, distension and overgrowth of the rete, distension and reduction in epithelial height of the efferent ducts, underdevelopment of the epididymal duct epithelium, reduction in epithelial height in the vas deferens, and convolution of the extra-epididymal vas. In DES-treated rats, androgen receptor (AR) immunoexpression was virtually absent from all affected tissues and the testis, whereas AR expression in controls was intense in epithelial and stromal cells. The DES-induced change in AR immunoexpression was confirmed by Western analysis for the testis. In rats treated neonatally with 1 microg DES, reproductive abnormalities were absent or minor, except for a 38% reduction in testis weight; loss of AR immunoexpression also did not occur in these rats. Treatment-induced changes in AR expression were paralleled by changes in Leydig cell volume per testis (91% reduction in the 10-microg DES group; no change in the 1-microg DES group). To test whether suppression of androgen production or action alone could induce comparable reproductive abnormalities to 10 microg DES, rats were treated neonatally with either a potent gonadotropin-releasing hormone antagonist (GnRHa) or with flutamide (50 mg/kg/day). These treatments reduced testis weight (68% for GnRHa, 40% for flutamide), and generally retarded development of the reproductive tract but failed to induce the abnormalities induced by 10 microg DES. GnRHa and flutamide caused no detectable change in AR immunoexpression in target tissues, with the exception of minor changes in the testes of flutamide-treated males. GnRHa treatment caused a reduction (83%) in Leydig cell volume comparable to that caused by 10 microg DES. Immunoexpression of estrogen receptor alpha (ER alpha) in the efferent ducts and of ER beta in all tissues studied were unaffected by any of the above treatments. Neonatal coadministration of testosterone esters (TE; 200 microg) with 10 microg DES prevented most of the morphological abnormalities induced by 10 microg DES treatment alone, though testis weight was still subnormal (46% reduction in DES + TE vs 72% in DES alone and 49% with TE alone) and some lumenal distension was still evident in the efferent ducts. Coadministration of TE with DES prevented DES-induced loss of AR immunoexpression (confirmed for testis by Western blot analysis). It is concluded that 1) reproductive tract abnormalities induced in the neonatal male rat by a high (10 microg) dose of DES are associated with reduced AR expression and Leydig cell volume; 2) these changes are largely absent with a lower dose of DES (1 microg); 3) treatments that interfere with androgen production (GnRHa) or action (flutamide) alone failed to induce reproductive tract abnormalities or alter AR expression as did 10 microg DES; 4) a grossly altered androgen:estrogen balance (low androgen + high estrogen) may underlie the reproductive tract abnormalities, other than reduced testis weight, induced by high doses of DES.

Androgen Antagonists↗
PubMed2000

Prevalence and significance of heterogeneous testes revealed on sonography: ex vivo sonographic-pathologic correlation.

OBJECTIVE: Heterogeneous or mottled testes in middle-aged or elderly men are often encountered on sonography. To determine the prevalence, cause, and significance of this finding, we examined 50 testes (25 pairs) from autopsy specimens with sonography and gross and microscopic pathology. SUBJECTS AND METHODS: Testicles were obtained at autopsy from a series of 25 male cadavers (age range, 16-80 years; mean, 62 years). Eight subjects had a history of cancer. Ex vivo sonography was performed and two board-certified radiologists graded the testis by consensus as normal, heterogeneous, or "other abnormality" (cyst, dilated rete, echogenic focus, or halo). Microscopic pathology was obtained in all abnormal (sonographic or gross pathologic) testes. The severity of tubular sclerosis (atrophy) was graded on a scale of 0-3+ by a uropathologist. RESULTS; No testicular tumors were detected. Sonography revealed normal testes in 33 specimens, heterogeneous in seven specimens, and other in 10 specimens (one cyst, two dilated rete, three halos, and seven echogenic foci). Histology revealed that all seven cases of mottled or heterogeneous testis corresponded to extensive (grades 2 and 3) regions of tubular sclerosis (atrophy). A new sonographic finding of the "halo" was attributable to a thickened, adherent tunica albuginea. CONCLUSION: The prevalence of heterogeneous testes in this elderly population was 14% and represented seminiferous tubule atrophy and sclerosis. The prevalence of clinically occult testicular cancer or metastases in this autopsy subject group was nil. Older patients with a mottled or heterogeneous testis, normal color Doppler flow, and no palpable abnormality probably do not need sonographic follow-up.

Adolescent↗